A $1 bonus for fresh produce about doubled purchases, and some of it lasted
Who it’s about: Adults
- Helped
Shoppers offered an extra $1 for 5 cups of produce bought about 3.4 cups a trip, against 1.6 without it.
- Rule: Get a reward or payment for doing ittested
- Rule: Reward yourself right aftertested
- Action: Eat fruit and vegetablesused
Randomised trial of 222 shoppers at a Chicago neighbourhood grocery store · vs shoppers with the same store card but no bonus · behaviour was recorded · ⚠ summary claims more than the results show; numbers unreliable; many people dropped out
- Mixed
After the bonus ended, bonus shoppers bought more cups of produce than those without it, but didn't spend clearly more.
Randomised trial of 222 shoppers at a Chicago neighbourhood grocery store · vs shoppers with the same store card but no bonus · behaviour was recorded · ⚠ summary claims more than the results show; numbers unreliable; many people dropped out
- No difference
Coupons with fruit and vegetable tips didn't change how much produce people bought, with or without the bonus.
Randomised trial of 222 shoppers at a Chicago neighbourhood grocery store · vs shoppers with the same store card but no tips · behaviour was recorded · ⚠ summary claims more than the results show; numbers unreliable; many people dropped out
The study
Who took part
222 adult shoppers at a small local grocery store in a part of Chicago, USA, where fresh food is hard to find. They were about 50 on average, about half were women, and about 9 in 10 were Black.
What they did
For about five months, every shopper got $1 per trip on a store card. One group also got an extra $1 on any trip with at least 5 cups of fruit or vegetables. Another got a tip on using fruit or vegetables each visit. A third got both, and the last got neither. The store kept track of what people bought for about six weeks after this stopped.
What happened
While the bonus ran, shoppers who got it bought about 3.4 cups of produce a trip, against 1.6 without it. Tips alone made no difference. In the six weeks after it stopped, bonus shoppers still bought about 2.5 cups a trip, against 1. But they didn't spend clearly more money on produce. Only 128 of the 222 shoppers came back after the bonus ended. Some of the paper's numbers, and a claim in its summary, don't match its tables.
Source
Incentives to Eat Healthy: Evidence from a Grocery Store Field Experiment (2015)
DOI: 10.2139/ssrn.2664818 (opens in a new tab)Tools in this study
Rule · how5
Get a reward or payment for doing itIncentives, prizes, lotteries or points for doing it.
Action4
Learn how the problem worksPsychoeducation about procrastination, habits, sleep, routines or ADHD.
